Cannon AFB, New MexicoNovember 1957

On the morning of November 6, 1957, radar operators at Cannon Air Force Base in New Mexico tracked a slow-moving object across their scopes. The object appeared to be about the size of an aircraft on the radar display. Over the course of approximately nine minutes, the radar showed the target moving from west to east at a speed of 60 to 70 miles per hour. The operators tracked 17 separate radar positions as the object traveled north of the station and then eastward, before the signal faded out completely about 15 to 20 nautical miles east of the base.

One additional radar contact occurred later that morning using IFF equipment (Identification Friend or Foe, a system that detects aircraft carrying special transponders). This target moved southbound from the base at a much faster speed of about 200 miles per hour. Because it was tracked on IFF equipment, Air Force engineers concluded it was almost certainly an aircraft, possibly a small Army plane or Civil Air Patrol aircraft equipped with a transponder.

The investigation that followed considered several explanations for the slower-moving targets. An Air Force intelligence analysis noted that migratory ducks had been observed on radar before at the base, and the targets' speed and behavior were consistent with birds. However, the analysts acknowledged this explanation did not account for the IFF sighting. The file also documents a separate sighting the same night: a meteor moving from south to north, visible for only two or three seconds, which the Air Force evaluated as an astronomical phenomenon.

The case file does not provide a definitive conclusion for the radar contacts. The Air Force evaluation form marked the case as "unidentified," while the intelligence summary suggested the slow radar targets were possibly migratory birds, though this remained unconfirmed. The full case file, comprising eight pages held by the National Archives, is reproduced below.